A5040284651- Luminescence Properties of Advanced Materials
- Pigment Synthesis and Properties
- Lanthanide and Transition Metal Complexes
- Iron oxide chemistry and applications
- Photonic Crystals and Applications
- Glass properties and applications
- Quantum Dots Synthesis And Properties
- Atomic and Subatomic Physics Research
- Gas Sensing Nanomaterials and Sensors
- Catalytic Processes in Materials Science
- Nuclear materials and radiation effects
- Advanced Photocatalysis Techniques
- Luminescence and Fluorescent Materials
- Inorganic Fluorides and Related Compounds
- Catalysis and Oxidation Reactions
- Cultural Heritage Materials Analysis
- Crystallization and Solubility Studies
- Advanced ceramic materials synthesis
- Microwave Dielectric Ceramics Synthesis
- Perovskite Materials and Applications
- TiO2 Photocatalysis and Solar Cells
- Magnetic Properties and Synthesis of Ferrites
- Advanced MRI Techniques and Applications
- Clay minerals and soil interactions
- Mineralogy and Gemology Studies
Instituto de Ciencia de Materiales de Sevilla
2015-2024
Universidad de Sevilla
2010-2023
Consejo Superior de Investigaciones Científicas
2006-2021
IVI Sevilla Clinic
2016-2021
Centro de Investigaciones Científicas Isla de la Cartuja
2008-2020
Instituto de Ciencia de Materiales de Madrid
1991-2010
Universidad Pablo de Olavide
2009
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2003
CEA Paris-Saclay
2003
Clarkson University
1990-1994
Abstract Rare earth based nanostructures constitute a type of functional materials widely used and studied in the recent literature. The purpose this review is to provide general comprehensive overview current state art, with special focus on commonly employed synthesis methods functionalization strategies rare nanoparticles their different bioimaging biosensing applications. luminescent (including downconversion, upconversion permanent luminescence) magnetic properties nanoparticles, as...
In this letter, we investigate the optical properties of packed monodisperse silica submicron spheres by means transmission measurements. The results are compatible with a three dimensional face centered cubic order in these solid structures. lattice parameter structures, and therefore their properties, can be easily tuned through sphere size (between 200 700 nm) thus covering whole visible near infrared spectrum.
A simple, reproducible, and reliable method to crystallize sub-micrometer-size spherical colloids using a mixture of volatile solvents as dispersion media is presented. Strongly diffracting direct opal structures high uniformity are attainable over large areas within minutes without further processing. Thickness orientation control also possible through this technique. In the figure, both [111] (left) [100] (right) oriented lattices deposited on glass slides shown.
The solar-to-electric power-conversion efficiency (η) of dye-sensitized solar cells can be greatly enhanced by integrating a mesoporous, nanoparticle-based, 1D photonic crystal as coherent scattering layer in the device. photogenerated current is improved without altering open-circuit voltage cell, while keeping transparency cell intact. Improved average η values between 15% and 30% are attained. Detailed facts importance to specialist readers published ”Supporting Information”. Such...
The thermal evolution of amorphous TiO 2 powders, consisting spherical particles and prepared by hydrolysis a titanium ethoxide aerosol, was studied using Raman spectroscopy. On calcination at 350°C, the solid crystallized, giving anatase as major phase. A small amount rutile also detected attributed to seeds localized particle outlayer. nucleation so low temperature ascribed presence organic impurities in powders. transformation into clearly observed after heating 660°C.
Monodisperse colloids have found a wide range of technolgoical applications, in fields as diverse ceramics, pigments, and catalysis. Recent work analyzing the mechanism formation particles is reviewed, facotrs influencing size shape colloids, such SiO 2 shown Figure, are discussed. magnified image
Isolated nanometric particles (D < 30 nm) of γ-Fe2O3 in a silica matrix have been prepared by heating at 400 °C the gel formed hydrolysis an ethanol solution Fe(NO3)3·9H2O and tetraethylorthosilicate (TEOS). However, when FeCl3·6H2O was used as precursor, well-developed hematite were obtained final composite. This different behavior already manifest initial gels. Thus, from iron nitrate salt shows compact appearance result its higher degree network connectivity (polymeric gel) whereas one...
Herein we present a fast, reliable method for building nanoparticle-based 1D photonic crystals in which periodic modulation of the refractive index is built by alternating different types nanoparticles and controlling level porosity each layer. The versatility further confirmed up optically doped opening transmission windows due to creation defect states gap demonstrated. potential this new type structure as sensing material illustrated analyzing specific color changes induced infiltration...
Europium-doped calcium hydroxyapatite and fluoroapatite nanophosphors functionalized with poly(acrylic acid) (PAA) have been synthesized through a one-pot microwave-assisted hydrothermal method from aqueous basic solutions containing nitrate, sodium phosphate monobasic, PAA, as well fluoride in the case of particles. In both cases spindlelike morphology was obtained, resulting an aggregation process smaller subunits which also gave rise to high specific surface area. The size nanospindles...
Zinc germanate doped with Mn2+ (Zn2GeO4:Mn2+) is known to be a persistent luminescence green phosphor potential applications in biosensing and bioimaging. Such demand nanoparticulated phosphors uniform shape size, good dispersibility aqueous media, high chemical stability, surface-functionalization. These characteristics could major bottlenecks hence limit their practical applications. This work describes one-pot, microwave-assisted hydrothermal method synthesize highly Zn2GeO4:Mn2+...
Since haematite ( alpha -Fe2O3) microcrystals are available with well defined shape (sphere, spindle and disc) size homogeneity, the authors have been able to check validity of classical theory absorption radiation by small particles in infrared. The agreement between observed calculated infrared spectra is very good once particle aggregation taken into consideration. Comparison experimental IR also affords a useful method for determination relative orientation crystallographic axes...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation and properties of uniform-coated colloidal particles. 6. Titania on zinc oxideManuel Ocana, Wan Peter Hsu, Egon MatijevicCite this: Langmuir 1991, 7, 12, 2911–2916Publication Date (Print):December 1, 1991Publication History Published online1 May 2002Published inissue 1 December 1991https://pubs.acs.org/doi/10.1021/la00060a008https://doi.org/10.1021/la00060a008research-articleACS PublicationsRequest reuse permissionsArticle...
Herein we report an analysis of the variation optical properties different nanoparticle-based one-dimensional photonic crystal architectures versus changes in ambient vapor pressure. Gradual shift response provides us with information on sorption these structures and allow to measure precise adsorption isotherms porous multilayers. The potential crystals as base materials for sensing devices is demonstrated this way.
A simple and fast (7 min) procedure for synthesis of gadolinium phosphate nanocubes (edge = 75 nm) based on the microwave-assisted heating at 120 °C acetylacetonate phosphoric acid solutions in buthylene glycol is reported. These were highly crystalline crystallized into a tetragonal structure, which has not been ever reported pure phosphate. Determination such crystal structure carried out here first time literature by means powder X-ray diffraction. The developed was also successful...
Mesoporous tetragonal RE:YPO4 nanophosphors (RE = Eu, Ce, Tb, and Ce + Tb) with a lenticular morphology, narrow size distribution, high surface area have been prepared by an homogeneous precipitation procedure consisting of aging, at low temperature (80–120 °C) in microwave oven, ethylene glycol solutions containing only yttrium acetylacetonate phosphoric acid. This synthesis method involves important advantages such as its simplicity, rapidness (reaction time 7 min), reaction yields. The...
A facile solvothermal route has been developed for the preparation of europium doped gadolinium orthovanadate nanoparticles (∼70 nm) with tetragonal structure, based on a homogenous precipitation reaction at 120 °C from rare earth precursors (yttrium nitrate and nitrate) sodium solutions using an ethylene glycol–water mixture as solvent. The effects doping level luminescence properties were evaluated in order to find optimum nanophosphors. These nanocrystals successfully functionalized amino...
Abstract A synthetic route to building photoconducting films of TiO 2 nanoparticles that display bright structural color is presented. The arises as a result the periodic modulation refractive index, which achieved by controlling degree porosity each alternate layer through particle size distribution precursor suspensions. suspensions are cast in shape film spin‐coating, allows tailoring lattice parameter multilayer, thus tuning Bragg peak spectral position (i.e., its color) over entire...
We describe a facile procedure for the synthesis of uniform lanthanide fluoride nanophosphors by homogeneous precipitation in ethylene glycol solutions containing precursors and an ionic liquid (1-butyl, 2-methylimidazolium tetrafluoroborate). It is shown that use this as source, appropriate choice solvent precursor, adjustment reaction temperature, are essential to obtain nanoparticles. This method applied preparation pure YF3, EuF3 TbF3 nanoparticles well Eu-doped YF3 Tb-doped YF3. In most...
The highly visible and infrared (up to 6 μm) transparent Sr3Al2O6 polycrystalline ceramic was obtained by full crystallization of the corresponding glass composition. synthesis direct congruent processes are described, material transparency is discussed in light its microstructure. This new exhibits a high density (i.e., complete absence porosity) micrometer-scale crystallites with very thin grain boundaries. These microstructural characteristics, inherent preparation method, minimize...
Near-ultraviolet and visible excitable Eu- Bi-doped NPs based on rare earth vanadates (REVO4, RE = Y, Gd) have been synthesized by a facile route from appropriate precursors, europium bismuth nitrate, sodium orthovanadate, homogeneous precipitation in an ethylene glycol/water mixture at 120 °C. The can be functionalized either one-pot synthesis with polyacrylic acid (PAA) or Layer-by-Layer approach poly(allylamine hydrochloride) (PAH) PAA. In the first case, particle size also tuned...
Why is the Eu<sup>3+</sup>:CaMoO<sub>4</sub>unit cell bigger than that of CaMoO<sub>4</sub>? Does Na<sup>+</sup>co-doping improve quantum yield Eu<sup>3+</sup>:CaMoO<sub>4</sub>phosphors?